diff options
Diffstat (limited to 'security/selinux/ss/services.c')
| -rw-r--r-- | security/selinux/ss/services.c | 4002 |
1 files changed, 4002 insertions, 0 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c new file mode 100644 index 000000000..3db8bd215 --- /dev/null +++ b/security/selinux/ss/services.c @@ -0,0 +1,4002 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Implementation of the security services. + * + * Authors : Stephen Smalley, <sds@tycho.nsa.gov> + * James Morris <jmorris@redhat.com> + * + * Updated: Trusted Computer Solutions, Inc. <dgoeddel@trustedcs.com> + * + * Support for enhanced MLS infrastructure. + * Support for context based audit filters. + * + * Updated: Frank Mayer <mayerf@tresys.com> and Karl MacMillan <kmacmillan@tresys.com> + * + * Added conditional policy language extensions + * + * Updated: Hewlett-Packard <paul@paul-moore.com> + * + * Added support for NetLabel + * Added support for the policy capability bitmap + * + * Updated: Chad Sellers <csellers@tresys.com> + * + * Added validation of kernel classes and permissions + * + * Updated: KaiGai Kohei <kaigai@ak.jp.nec.com> + * + * Added support for bounds domain and audit messaged on masked permissions + * + * Updated: Guido Trentalancia <guido@trentalancia.com> + * + * Added support for runtime switching of the policy type + * + * Copyright (C) 2008, 2009 NEC Corporation + * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. + * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC + * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> + */ +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/spinlock.h> +#include <linux/rcupdate.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/sched.h> +#include <linux/audit.h> +#include <linux/vmalloc.h> +#include <net/netlabel.h> + +#include "flask.h" +#include "avc.h" +#include "avc_ss.h" +#include "security.h" +#include "context.h" +#include "policydb.h" +#include "sidtab.h" +#include "services.h" +#include "conditional.h" +#include "mls.h" +#include "objsec.h" +#include "netlabel.h" +#include "xfrm.h" +#include "ebitmap.h" +#include "audit.h" +#include "policycap_names.h" + +struct convert_context_args { + struct selinux_state *state; + struct policydb *oldp; + struct policydb *newp; +}; + +struct selinux_policy_convert_data { + struct convert_context_args args; + struct sidtab_convert_params sidtab_params; +}; + +/* Forward declaration. */ +static int context_struct_to_string(struct policydb *policydb, + struct context *context, + char **scontext, + u32 *scontext_len); + +static int sidtab_entry_to_string(struct policydb *policydb, + struct sidtab *sidtab, + struct sidtab_entry *entry, + char **scontext, + u32 *scontext_len); + +static void context_struct_compute_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + struct av_decision *avd, + struct extended_perms *xperms); + +static int selinux_set_mapping(struct policydb *pol, + struct security_class_mapping *map, + struct selinux_map *out_map) +{ + u16 i, j; + unsigned k; + bool print_unknown_handle = false; + + /* Find number of classes in the input mapping */ + if (!map) + return -EINVAL; + i = 0; + while (map[i].name) + i++; + + /* Allocate space for the class records, plus one for class zero */ + out_map->mapping = kcalloc(++i, sizeof(*out_map->mapping), GFP_ATOMIC); + if (!out_map->mapping) + return -ENOMEM; + + /* Store the raw class and permission values */ + j = 0; + while (map[j].name) { + struct security_class_mapping *p_in = map + (j++); + struct selinux_mapping *p_out = out_map->mapping + j; + + /* An empty class string skips ahead */ + if (!strcmp(p_in->name, "")) { + p_out->num_perms = 0; + continue; + } + + p_out->value = string_to_security_class(pol, p_in->name); + if (!p_out->value) { + pr_info("SELinux: Class %s not defined in policy.\n", + p_in->name); + if (pol->reject_unknown) + goto err; + p_out->num_perms = 0; + print_unknown_handle = true; + continue; + } + + k = 0; + while (p_in->perms[k]) { + /* An empty permission string skips ahead */ + if (!*p_in->perms[k]) { + k++; + continue; + } + p_out->perms[k] = string_to_av_perm(pol, p_out->value, + p_in->perms[k]); + if (!p_out->perms[k]) { + pr_info("SELinux: Permission %s in class %s not defined in policy.\n", + p_in->perms[k], p_in->name); + if (pol->reject_unknown) + goto err; + print_unknown_handle = true; + } + + k++; + } + p_out->num_perms = k; + } + + if (print_unknown_handle) + pr_info("SELinux: the above unknown classes and permissions will be %s\n", + pol->allow_unknown ? "allowed" : "denied"); + + out_map->size = i; + return 0; +err: + kfree(out_map->mapping); + out_map->mapping = NULL; + return -EINVAL; +} + +/* + * Get real, policy values from mapped values + */ + +static u16 unmap_class(struct selinux_map *map, u16 tclass) +{ + if (tclass < map->size) + return map->mapping[tclass].value; + + return tclass; +} + +/* + * Get kernel value for class from its policy value + */ +static u16 map_class(struct selinux_map *map, u16 pol_value) +{ + u16 i; + + for (i = 1; i < map->size; i++) { + if (map->mapping[i].value == pol_value) + return i; + } + + return SECCLASS_NULL; +} + +static void map_decision(struct selinux_map *map, + u16 tclass, struct av_decision *avd, + int allow_unknown) +{ + if (tclass < map->size) { + struct selinux_mapping *mapping = &map->mapping[tclass]; + unsigned int i, n = mapping->num_perms; + u32 result; + + for (i = 0, result = 0; i < n; i++) { + if (avd->allowed & mapping->perms[i]) + result |= 1<<i; + if (allow_unknown && !mapping->perms[i]) + result |= 1<<i; + } + avd->allowed = result; + + for (i = 0, result = 0; i < n; i++) + if (avd->auditallow & mapping->perms[i]) + result |= 1<<i; + avd->auditallow = result; + + for (i = 0, result = 0; i < n; i++) { + if (avd->auditdeny & mapping->perms[i]) + result |= 1<<i; + if (!allow_unknown && !mapping->perms[i]) + result |= 1<<i; + } + /* + * In case the kernel has a bug and requests a permission + * between num_perms and the maximum permission number, we + * should audit that denial + */ + for (; i < (sizeof(u32)*8); i++) + result |= 1<<i; + avd->auditdeny = result; + } +} + +int security_mls_enabled(struct selinux_state *state) +{ + int mls_enabled; + struct selinux_policy *policy; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + mls_enabled = policy->policydb.mls_enabled; + rcu_read_unlock(); + return mls_enabled; +} + +/* + * Return the boolean value of a constraint expression + * when it is applied to the specified source and target + * security contexts. + * + * xcontext is a special beast... It is used by the validatetrans rules + * only. For these rules, scontext is the context before the transition, + * tcontext is the context after the transition, and xcontext is the context + * of the process performing the transition. All other callers of + * constraint_expr_eval should pass in NULL for xcontext. + */ +static int constraint_expr_eval(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + struct context *xcontext, + struct constraint_expr *cexpr) +{ + u32 val1, val2; + struct context *c; + struct role_datum *r1, *r2; + struct mls_level *l1, *l2; + struct constraint_expr *e; + int s[CEXPR_MAXDEPTH]; + int sp = -1; + + for (e = cexpr; e; e = e->next) { + switch (e->expr_type) { + case CEXPR_NOT: + BUG_ON(sp < 0); + s[sp] = !s[sp]; + break; + case CEXPR_AND: + BUG_ON(sp < 1); + sp--; + s[sp] &= s[sp + 1]; + break; + case CEXPR_OR: + BUG_ON(sp < 1); + sp--; + s[sp] |= s[sp + 1]; + break; + case CEXPR_ATTR: + if (sp == (CEXPR_MAXDEPTH - 1)) + return 0; + switch (e->attr) { + case CEXPR_USER: + val1 = scontext->user; + val2 = tcontext->user; + break; + case CEXPR_TYPE: + val1 = scontext->type; + val2 = tcontext->type; + break; + case CEXPR_ROLE: + val1 = scontext->role; + val2 = tcontext->role; + r1 = policydb->role_val_to_struct[val1 - 1]; + r2 = policydb->role_val_to_struct[val2 - 1]; + switch (e->op) { + case CEXPR_DOM: + s[++sp] = ebitmap_get_bit(&r1->dominates, + val2 - 1); + continue; + case CEXPR_DOMBY: + s[++sp] = ebitmap_get_bit(&r2->dominates, + val1 - 1); + continue; + case CEXPR_INCOMP: + s[++sp] = (!ebitmap_get_bit(&r1->dominates, + val2 - 1) && + !ebitmap_get_bit(&r2->dominates, + val1 - 1)); + continue; + default: + break; + } + break; + case CEXPR_L1L2: + l1 = &(scontext->range.level[0]); + l2 = &(tcontext->range.level[0]); + goto mls_ops; + case CEXPR_L1H2: + l1 = &(scontext->range.level[0]); + l2 = &(tcontext->range.level[1]); + goto mls_ops; + case CEXPR_H1L2: + l1 = &(scontext->range.level[1]); + l2 = &(tcontext->range.level[0]); + goto mls_ops; + case CEXPR_H1H2: + l1 = &(scontext->range.level[1]); + l2 = &(tcontext->range.level[1]); + goto mls_ops; + case CEXPR_L1H1: + l1 = &(scontext->range.level[0]); + l2 = &(scontext->range.level[1]); + goto mls_ops; + case CEXPR_L2H2: + l1 = &(tcontext->range.level[0]); + l2 = &(tcontext->range.level[1]); + goto mls_ops; +mls_ops: + switch (e->op) { + case CEXPR_EQ: + s[++sp] = mls_level_eq(l1, l2); + continue; + case CEXPR_NEQ: + s[++sp] = !mls_level_eq(l1, l2); + continue; + case CEXPR_DOM: + s[++sp] = mls_level_dom(l1, l2); + continue; + case CEXPR_DOMBY: + s[++sp] = mls_level_dom(l2, l1); + continue; + case CEXPR_INCOMP: + s[++sp] = mls_level_incomp(l2, l1); + continue; + default: + BUG(); + return 0; + } + break; + default: + BUG(); + return 0; + } + + switch (e->op) { + case CEXPR_EQ: + s[++sp] = (val1 == val2); + break; + case CEXPR_NEQ: + s[++sp] = (val1 != val2); + break; + default: + BUG(); + return 0; + } + break; + case CEXPR_NAMES: + if (sp == (CEXPR_MAXDEPTH-1)) + return 0; + c = scontext; + if (e->attr & CEXPR_TARGET) + c = tcontext; + else if (e->attr & CEXPR_XTARGET) { + c = xcontext; + if (!c) { + BUG(); + return 0; + } + } + if (e->attr & CEXPR_USER) + val1 = c->user; + else if (e->attr & CEXPR_ROLE) + val1 = c->role; + else if (e->attr & CEXPR_TYPE) + val1 = c->type; + else { + BUG(); + return 0; + } + + switch (e->op) { + case CEXPR_EQ: + s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); + break; + case CEXPR_NEQ: + s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); + break; + default: + BUG(); + return 0; + } + break; + default: + BUG(); + return 0; + } + } + + BUG_ON(sp != 0); + return s[0]; +} + +/* + * security_dump_masked_av - dumps masked permissions during + * security_compute_av due to RBAC, MLS/Constraint and Type bounds. + */ +static int dump_masked_av_helper(void *k, void *d, void *args) +{ + struct perm_datum *pdatum = d; + char **permission_names = args; + + BUG_ON(pdatum->value < 1 || pdatum->value > 32); + + permission_names[pdatum->value - 1] = (char *)k; + + return 0; +} + +static void security_dump_masked_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + u32 permissions, + const char *reason) +{ + struct common_datum *common_dat; + struct class_datum *tclass_dat; + struct audit_buffer *ab; + char *tclass_name; + char *scontext_name = NULL; + char *tcontext_name = NULL; + char *permission_names[32]; + int index; + u32 length; + bool need_comma = false; + + if (!permissions) + return; + + tclass_name = sym_name(policydb, SYM_CLASSES, tclass - 1); + tclass_dat = policydb->class_val_to_struct[tclass - 1]; + common_dat = tclass_dat->comdatum; + + /* init permission_names */ + if (common_dat && + hashtab_map(&common_dat->permissions.table, + dump_masked_av_helper, permission_names) < 0) + goto out; + + if (hashtab_map(&tclass_dat->permissions.table, + dump_masked_av_helper, permission_names) < 0) + goto out; + + /* get scontext/tcontext in text form */ + if (context_struct_to_string(policydb, scontext, + &scontext_name, &length) < 0) + goto out; + + if (context_struct_to_string(policydb, tcontext, + &tcontext_name, &length) < 0) + goto out; + + /* audit a message */ + ab = audit_log_start(audit_context(), + GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + goto out; + + audit_log_format(ab, "op=security_compute_av reason=%s " + "scontext=%s tcontext=%s tclass=%s perms=", + reason, scontext_name, tcontext_name, tclass_name); + + for (index = 0; index < 32; index++) { + u32 mask = (1 << index); + + if ((mask & permissions) == 0) + continue; + + audit_log_format(ab, "%s%s", + need_comma ? "," : "", + permission_names[index] + ? permission_names[index] : "????"); + need_comma = true; + } + audit_log_end(ab); +out: + /* release scontext/tcontext */ + kfree(tcontext_name); + kfree(scontext_name); + + return; +} + +/* + * security_boundary_permission - drops violated permissions + * on boundary constraint. + */ +static void type_attribute_bounds_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + struct av_decision *avd) +{ + struct context lo_scontext; + struct context lo_tcontext, *tcontextp = tcontext; + struct av_decision lo_avd; + struct type_datum *source; + struct type_datum *target; + u32 masked = 0; + + source = policydb->type_val_to_struct[scontext->type - 1]; + BUG_ON(!source); + + if (!source->bounds) + return; + + target = policydb->type_val_to_struct[tcontext->type - 1]; + BUG_ON(!target); + + memset(&lo_avd, 0, sizeof(lo_avd)); + + memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); + lo_scontext.type = source->bounds; + + if (target->bounds) { + memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); + lo_tcontext.type = target->bounds; + tcontextp = &lo_tcontext; + } + + context_struct_compute_av(policydb, &lo_scontext, + tcontextp, + tclass, + &lo_avd, + NULL); + + masked = ~lo_avd.allowed & avd->allowed; + + if (likely(!masked)) + return; /* no masked permission */ + + /* mask violated permissions */ + avd->allowed &= ~masked; + + /* audit masked permissions */ + security_dump_masked_av(policydb, scontext, tcontext, + tclass, masked, "bounds"); +} + +/* + * flag which drivers have permissions + * only looking for ioctl based extended permssions + */ +void services_compute_xperms_drivers( + struct extended_perms *xperms, + struct avtab_node *node) +{ + unsigned int i; + + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + /* if one or more driver has all permissions allowed */ + for (i = 0; i < ARRAY_SIZE(xperms->drivers.p); i++) + xperms->drivers.p[i] |= node->datum.u.xperms->perms.p[i]; + } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + /* if allowing permissions within a driver */ + security_xperm_set(xperms->drivers.p, + node->datum.u.xperms->driver); + } + + /* If no ioctl commands are allowed, ignore auditallow and auditdeny */ + if (node->key.specified & AVTAB_XPERMS_ALLOWED) + xperms->len = 1; +} + +/* + * Compute access vectors and extended permissions based on a context + * structure pair for the permissions in a particular class. + */ +static void context_struct_compute_av(struct policydb *policydb, + struct context *scontext, + struct context *tcontext, + u16 tclass, + struct av_decision *avd, + struct extended_perms *xperms) +{ + struct constraint_node *constraint; + struct role_allow *ra; + struct avtab_key avkey; + struct avtab_node *node; + struct class_datum *tclass_datum; + struct ebitmap *sattr, *tattr; + struct ebitmap_node *snode, *tnode; + unsigned int i, j; + + avd->allowed = 0; + avd->auditallow = 0; + avd->auditdeny = 0xffffffff; + if (xperms) { + memset(&xperms->drivers, 0, sizeof(xperms->drivers)); + xperms->len = 0; + } + + if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { + if (printk_ratelimit()) + pr_warn("SELinux: Invalid class %hu\n", tclass); + return; + } + + tclass_datum = policydb->class_val_to_struct[tclass - 1]; + + /* + * If a specific type enforcement rule was defined for + * this permission check, then use it. + */ + avkey.target_class = tclass; + avkey.specified = AVTAB_AV | AVTAB_XPERMS; + sattr = &policydb->type_attr_map_array[scontext->type - 1]; + tattr = &policydb->type_attr_map_array[tcontext->type - 1]; + ebitmap_for_each_positive_bit(sattr, snode, i) { + ebitmap_for_each_positive_bit(tattr, tnode, j) { + avkey.source_type = i + 1; + avkey.target_type = j + 1; + for (node = avtab_search_node(&policydb->te_avtab, + &avkey); + node; + node = avtab_search_node_next(node, avkey.specified)) { + if (node->key.specified == AVTAB_ALLOWED) + avd->allowed |= node->datum.u.data; + else if (node->key.specified == AVTAB_AUDITALLOW) + avd->auditallow |= node->datum.u.data; + else if (node->key.specified == AVTAB_AUDITDENY) + avd->auditdeny &= node->datum.u.data; + else if (xperms && (node->key.specified & AVTAB_XPERMS)) + services_compute_xperms_drivers(xperms, node); + } + + /* Check conditional av table for additional permissions */ + cond_compute_av(&policydb->te_cond_avtab, &avkey, + avd, xperms); + + } + } + + /* + * Remove any permissions prohibited by a constraint (this includes + * the MLS policy). + */ + constraint = tclass_datum->constraints; + while (constraint) { + if ((constraint->permissions & (avd->allowed)) && + !constraint_expr_eval(policydb, scontext, tcontext, NULL, + constraint->expr)) { + avd->allowed &= ~(constraint->permissions); + } + constraint = constraint->next; + } + + /* + * If checking process transition permission and the + * role is changing, then check the (current_role, new_role) + * pair. + */ + if (tclass == policydb->process_class && + (avd->allowed & policydb->process_trans_perms) && + scontext->role != tcontext->role) { + for (ra = policydb->role_allow; ra; ra = ra->next) { + if (scontext->role == ra->role && + tcontext->role == ra->new_role) + break; + } + if (!ra) + avd->allowed &= ~policydb->process_trans_perms; + } + + /* + * If the given source and target types have boundary + * constraint, lazy checks have to mask any violated + * permission and notice it to userspace via audit. + */ + type_attribute_bounds_av(policydb, scontext, tcontext, + tclass, avd); +} + +static int security_validtrans_handle_fail(struct selinux_state *state, + struct selinux_policy *policy, + struct sidtab_entry *oentry, + struct sidtab_entry *nentry, + struct sidtab_entry *tentry, + u16 tclass) +{ + struct policydb *p = &policy->policydb; + struct sidtab *sidtab = policy->sidtab; + char *o = NULL, *n = NULL, *t = NULL; + u32 olen, nlen, tlen; + + if (sidtab_entry_to_string(p, sidtab, oentry, &o, &olen)) + goto out; + if (sidtab_entry_to_string(p, sidtab, nentry, &n, &nlen)) + goto out; + if (sidtab_entry_to_string(p, sidtab, tentry, &t, &tlen)) + goto out; + audit_log(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR, + "op=security_validate_transition seresult=denied" + " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", + o, n, t, sym_name(p, SYM_CLASSES, tclass-1)); +out: + kfree(o); + kfree(n); + kfree(t); + + if (!enforcing_enabled(state)) + return 0; + return -EPERM; +} + +static int security_compute_validatetrans(struct selinux_state *state, + u32 oldsid, u32 newsid, u32 tasksid, + u16 orig_tclass, bool user) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct sidtab_entry *oentry; + struct sidtab_entry *nentry; + struct sidtab_entry *tentry; + struct class_datum *tclass_datum; + struct constraint_node *constraint; + u16 tclass; + int rc = 0; + + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (!user) + tclass = unmap_class(&policy->map, orig_tclass); + else + tclass = orig_tclass; + + if (!tclass || tclass > policydb->p_classes.nprim) { + rc = -EINVAL; + goto out; + } + tclass_datum = policydb->class_val_to_struct[tclass - 1]; + + oentry = sidtab_search_entry(sidtab, oldsid); + if (!oentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, oldsid); + rc = -EINVAL; + goto out; + } + + nentry = sidtab_search_entry(sidtab, newsid); + if (!nentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, newsid); + rc = -EINVAL; + goto out; + } + + tentry = sidtab_search_entry(sidtab, tasksid); + if (!tentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tasksid); + rc = -EINVAL; + goto out; + } + + constraint = tclass_datum->validatetrans; + while (constraint) { + if (!constraint_expr_eval(policydb, &oentry->context, + &nentry->context, &tentry->context, + constraint->expr)) { + if (user) + rc = -EPERM; + else + rc = security_validtrans_handle_fail(state, + policy, + oentry, + nentry, + tentry, + tclass); + goto out; + } + constraint = constraint->next; + } + +out: + rcu_read_unlock(); + return rc; +} + +int security_validate_transition_user(struct selinux_state *state, + u32 oldsid, u32 newsid, u32 tasksid, + u16 tclass) +{ + return security_compute_validatetrans(state, oldsid, newsid, tasksid, + tclass, true); +} + +int security_validate_transition(struct selinux_state *state, + u32 oldsid, u32 newsid, u32 tasksid, + u16 orig_tclass) +{ + return security_compute_validatetrans(state, oldsid, newsid, tasksid, + orig_tclass, false); +} + +/* + * security_bounded_transition - check whether the given + * transition is directed to bounded, or not. + * It returns 0, if @newsid is bounded by @oldsid. + * Otherwise, it returns error code. + * + * @oldsid : current security identifier + * @newsid : destinated security identifier + */ +int security_bounded_transition(struct selinux_state *state, + u32 old_sid, u32 new_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct sidtab_entry *old_entry, *new_entry; + struct type_datum *type; + int index; + int rc; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + rc = -EINVAL; + old_entry = sidtab_search_entry(sidtab, old_sid); + if (!old_entry) { + pr_err("SELinux: %s: unrecognized SID %u\n", + __func__, old_sid); + goto out; + } + + rc = -EINVAL; + new_entry = sidtab_search_entry(sidtab, new_sid); + if (!new_entry) { + pr_err("SELinux: %s: unrecognized SID %u\n", + __func__, new_sid); + goto out; + } + + rc = 0; + /* type/domain unchanged */ + if (old_entry->context.type == new_entry->context.type) + goto out; + + index = new_entry->context.type; + while (true) { + type = policydb->type_val_to_struct[index - 1]; + BUG_ON(!type); + + /* not bounded anymore */ + rc = -EPERM; + if (!type->bounds) + break; + + /* @newsid is bounded by @oldsid */ + rc = 0; + if (type->bounds == old_entry->context.type) + break; + + index = type->bounds; + } + + if (rc) { + char *old_name = NULL; + char *new_name = NULL; + u32 length; + + if (!sidtab_entry_to_string(policydb, sidtab, old_entry, + &old_name, &length) && + !sidtab_entry_to_string(policydb, sidtab, new_entry, + &new_name, &length)) { + audit_log(audit_context(), + GFP_ATOMIC, AUDIT_SELINUX_ERR, + "op=security_bounded_transition " + "seresult=denied " + "oldcontext=%s newcontext=%s", + old_name, new_name); + } + kfree(new_name); + kfree(old_name); + } +out: + rcu_read_unlock(); + + return rc; +} + +static void avd_init(struct selinux_policy *policy, struct av_decision *avd) +{ + avd->allowed = 0; + avd->auditallow = 0; + avd->auditdeny = 0xffffffff; + if (policy) + avd->seqno = policy->latest_granting; + else + avd->seqno = 0; + avd->flags = 0; +} + +void services_compute_xperms_decision(struct extended_perms_decision *xpermd, + struct avtab_node *node) +{ + unsigned int i; + + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + if (xpermd->driver != node->datum.u.xperms->driver) + return; + } else if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + if (!security_xperm_test(node->datum.u.xperms->perms.p, + xpermd->driver)) + return; + } else { + BUG(); + } + + if (node->key.specified == AVTAB_XPERMS_ALLOWED) { + xpermd->used |= XPERMS_ALLOWED; + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + memset(xpermd->allowed->p, 0xff, + sizeof(xpermd->allowed->p)); + } + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + for (i = 0; i < ARRAY_SIZE(xpermd->allowed->p); i++) + xpermd->allowed->p[i] |= + node->datum.u.xperms->perms.p[i]; + } + } else if (node->key.specified == AVTAB_XPERMS_AUDITALLOW) { + xpermd->used |= XPERMS_AUDITALLOW; + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + memset(xpermd->auditallow->p, 0xff, + sizeof(xpermd->auditallow->p)); + } + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + for (i = 0; i < ARRAY_SIZE(xpermd->auditallow->p); i++) + xpermd->auditallow->p[i] |= + node->datum.u.xperms->perms.p[i]; + } + } else if (node->key.specified == AVTAB_XPERMS_DONTAUDIT) { + xpermd->used |= XPERMS_DONTAUDIT; + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLDRIVER) { + memset(xpermd->dontaudit->p, 0xff, + sizeof(xpermd->dontaudit->p)); + } + if (node->datum.u.xperms->specified == AVTAB_XPERMS_IOCTLFUNCTION) { + for (i = 0; i < ARRAY_SIZE(xpermd->dontaudit->p); i++) + xpermd->dontaudit->p[i] |= + node->datum.u.xperms->perms.p[i]; + } + } else { + BUG(); + } +} + +void security_compute_xperms_decision(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 orig_tclass, + u8 driver, + struct extended_perms_decision *xpermd) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + u16 tclass; + struct context *scontext, *tcontext; + struct avtab_key avkey; + struct avtab_node *node; + struct ebitmap *sattr, *tattr; + struct ebitmap_node *snode, *tnode; + unsigned int i, j; + + xpermd->driver = driver; + xpermd->used = 0; + memset(xpermd->allowed->p, 0, sizeof(xpermd->allowed->p)); + memset(xpermd->auditallow->p, 0, sizeof(xpermd->auditallow->p)); + memset(xpermd->dontaudit->p, 0, sizeof(xpermd->dontaudit->p)); + + rcu_read_lock(); + if (!selinux_initialized(state)) + goto allow; + + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + scontext = sidtab_search(sidtab, ssid); + if (!scontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + tcontext = sidtab_search(sidtab, tsid); + if (!tcontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + tclass = unmap_class(&policy->map, orig_tclass); + if (unlikely(orig_tclass && !tclass)) { + if (policydb->allow_unknown) + goto allow; + goto out; + } + + + if (unlikely(!tclass || tclass > policydb->p_classes.nprim)) { + pr_warn_ratelimited("SELinux: Invalid class %hu\n", tclass); + goto out; + } + + avkey.target_class = tclass; + avkey.specified = AVTAB_XPERMS; + sattr = &policydb->type_attr_map_array[scontext->type - 1]; + tattr = &policydb->type_attr_map_array[tcontext->type - 1]; + ebitmap_for_each_positive_bit(sattr, snode, i) { + ebitmap_for_each_positive_bit(tattr, tnode, j) { + avkey.source_type = i + 1; + avkey.target_type = j + 1; + for (node = avtab_search_node(&policydb->te_avtab, + &avkey); + node; + node = avtab_search_node_next(node, avkey.specified)) + services_compute_xperms_decision(xpermd, node); + + cond_compute_xperms(&policydb->te_cond_avtab, + &avkey, xpermd); + } + } +out: + rcu_read_unlock(); + return; +allow: + memset(xpermd->allowed->p, 0xff, sizeof(xpermd->allowed->p)); + goto out; +} + +/** + * security_compute_av - Compute access vector decisions. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @avd: access vector decisions + * @xperms: extended permissions + * + * Compute a set of access vector decisions based on the + * SID pair (@ssid, @tsid) for the permissions in @tclass. + */ +void security_compute_av(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 orig_tclass, + struct av_decision *avd, + struct extended_perms *xperms) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + u16 tclass; + struct context *scontext = NULL, *tcontext = NULL; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + avd_init(policy, avd); + xperms->len = 0; + if (!selinux_initialized(state)) + goto allow; + + policydb = &policy->policydb; + sidtab = policy->sidtab; + + scontext = sidtab_search(sidtab, ssid); + if (!scontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + /* permissive domain? */ + if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) + avd->flags |= AVD_FLAGS_PERMISSIVE; + + tcontext = sidtab_search(sidtab, tsid); + if (!tcontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + tclass = unmap_class(&policy->map, orig_tclass); + if (unlikely(orig_tclass && !tclass)) { + if (policydb->allow_unknown) + goto allow; + goto out; + } + context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, + xperms); + map_decision(&policy->map, orig_tclass, avd, + policydb->allow_unknown); +out: + rcu_read_unlock(); + return; +allow: + avd->allowed = 0xffffffff; + goto out; +} + +void security_compute_av_user(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 tclass, + struct av_decision *avd) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct context *scontext = NULL, *tcontext = NULL; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + avd_init(policy, avd); + if (!selinux_initialized(state)) + goto allow; + + policydb = &policy->policydb; + sidtab = policy->sidtab; + + scontext = sidtab_search(sidtab, ssid); + if (!scontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + goto out; + } + + /* permissive domain? */ + if (ebitmap_get_bit(&policydb->permissive_map, scontext->type)) + avd->flags |= AVD_FLAGS_PERMISSIVE; + + tcontext = sidtab_search(sidtab, tsid); + if (!tcontext) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + goto out; + } + + if (unlikely(!tclass)) { + if (policydb->allow_unknown) + goto allow; + goto out; + } + + context_struct_compute_av(policydb, scontext, tcontext, tclass, avd, + NULL); + out: + rcu_read_unlock(); + return; +allow: + avd->allowed = 0xffffffff; + goto out; +} + +/* + * Write the security context string representation of + * the context structure `context' into a dynamically + * allocated string of the correct size. Set `*scontext' + * to point to this string and set `*scontext_len' to + * the length of the string. + */ +static int context_struct_to_string(struct policydb *p, + struct context *context, + char **scontext, u32 *scontext_len) +{ + char *scontextp; + + if (scontext) + *scontext = NULL; + *scontext_len = 0; + + if (context->len) { + *scontext_len = context->len; + if (scontext) { + *scontext = kstrdup(context->str, GFP_ATOMIC); + if (!(*scontext)) + return -ENOMEM; + } + return 0; + } + + /* Compute the size of the context. */ + *scontext_len += strlen(sym_name(p, SYM_USERS, context->user - 1)) + 1; + *scontext_len += strlen(sym_name(p, SYM_ROLES, context->role - 1)) + 1; + *scontext_len += strlen(sym_name(p, SYM_TYPES, context->type - 1)) + 1; + *scontext_len += mls_compute_context_len(p, context); + + if (!scontext) + return 0; + + /* Allocate space for the context; caller must free this space. */ + scontextp = kmalloc(*scontext_len, GFP_ATOMIC); + if (!scontextp) + return -ENOMEM; + *scontext = scontextp; + + /* + * Copy the user name, role name and type name into the context. + */ + scontextp += sprintf(scontextp, "%s:%s:%s", + sym_name(p, SYM_USERS, context->user - 1), + sym_name(p, SYM_ROLES, context->role - 1), + sym_name(p, SYM_TYPES, context->type - 1)); + + mls_sid_to_context(p, context, &scontextp); + + *scontextp = 0; + + return 0; +} + +static int sidtab_entry_to_string(struct policydb *p, + struct sidtab *sidtab, + struct sidtab_entry *entry, + char **scontext, u32 *scontext_len) +{ + int rc = sidtab_sid2str_get(sidtab, entry, scontext, scontext_len); + + if (rc != -ENOENT) + return rc; + + rc = context_struct_to_string(p, &entry->context, scontext, + scontext_len); + if (!rc && scontext) + sidtab_sid2str_put(sidtab, entry, *scontext, *scontext_len); + return rc; +} + +#include "initial_sid_to_string.h" + +int security_sidtab_hash_stats(struct selinux_state *state, char *page) +{ + struct selinux_policy *policy; + int rc; + + if (!selinux_initialized(state)) { + pr_err("SELinux: %s: called before initial load_policy\n", + __func__); + return -EINVAL; + } + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + rc = sidtab_hash_stats(policy->sidtab, page); + rcu_read_unlock(); + + return rc; +} + +const char *security_get_initial_sid_context(u32 sid) +{ + if (unlikely(sid > SECINITSID_NUM)) + return NULL; + return initial_sid_to_string[sid]; +} + +static int security_sid_to_context_core(struct selinux_state *state, + u32 sid, char **scontext, + u32 *scontext_len, int force, + int only_invalid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct sidtab_entry *entry; + int rc = 0; + + if (scontext) + *scontext = NULL; + *scontext_len = 0; + + if (!selinux_initialized(state)) { + if (sid <= SECINITSID_NUM) { + char *scontextp; + const char *s = initial_sid_to_string[sid]; + + if (!s) + return -EINVAL; + *scontext_len = strlen(s) + 1; + if (!scontext) + return 0; + scontextp = kmemdup(s, *scontext_len, GFP_ATOMIC); + if (!scontextp) + return -ENOMEM; + *scontext = scontextp; + return 0; + } + pr_err("SELinux: %s: called before initial " + "load_policy on unknown SID %d\n", __func__, sid); + return -EINVAL; + } + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (force) + entry = sidtab_search_entry_force(sidtab, sid); + else + entry = sidtab_search_entry(sidtab, sid); + if (!entry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, sid); + rc = -EINVAL; + goto out_unlock; + } + if (only_invalid && !entry->context.len) + goto out_unlock; + + rc = sidtab_entry_to_string(policydb, sidtab, entry, scontext, + scontext_len); + +out_unlock: + rcu_read_unlock(); + return rc; + +} + +/** + * security_sid_to_context - Obtain a context for a given SID. + * @sid: security identifier, SID + * @scontext: security context + * @scontext_len: length in bytes + * + * Write the string representation of the context associated with @sid + * into a dynamically allocated string of the correct size. Set @scontext + * to point to this string and set @scontext_len to the length of the string. + */ +int security_sid_to_context(struct selinux_state *state, + u32 sid, char **scontext, u32 *scontext_len) +{ + return security_sid_to_context_core(state, sid, scontext, + scontext_len, 0, 0); +} + +int security_sid_to_context_force(struct selinux_state *state, u32 sid, + char **scontext, u32 *scontext_len) +{ + return security_sid_to_context_core(state, sid, scontext, + scontext_len, 1, 0); +} + +/** + * security_sid_to_context_inval - Obtain a context for a given SID if it + * is invalid. + * @sid: security identifier, SID + * @scontext: security context + * @scontext_len: length in bytes + * + * Write the string representation of the context associated with @sid + * into a dynamically allocated string of the correct size, but only if the + * context is invalid in the current policy. Set @scontext to point to + * this string (or NULL if the context is valid) and set @scontext_len to + * the length of the string (or 0 if the context is valid). + */ +int security_sid_to_context_inval(struct selinux_state *state, u32 sid, + char **scontext, u32 *scontext_len) +{ + return security_sid_to_context_core(state, sid, scontext, + scontext_len, 1, 1); +} + +/* + * Caveat: Mutates scontext. + */ +static int string_to_context_struct(struct policydb *pol, + struct sidtab *sidtabp, + char *scontext, + struct context *ctx, + u32 def_sid) +{ + struct role_datum *role; + struct type_datum *typdatum; + struct user_datum *usrdatum; + char *scontextp, *p, oldc; + int rc = 0; + + context_init(ctx); + + /* Parse the security context. */ + + rc = -EINVAL; + scontextp = (char *) scontext; + + /* Extract the user. */ + p = scontextp; + while (*p && *p != ':') + p++; + + if (*p == 0) + goto out; + + *p++ = 0; + + usrdatum = symtab_search(&pol->p_users, scontextp); + if (!usrdatum) + goto out; + + ctx->user = usrdatum->value; + + /* Extract role. */ + scontextp = p; + while (*p && *p != ':') + p++; + + if (*p == 0) + goto out; + + *p++ = 0; + + role = symtab_search(&pol->p_roles, scontextp); + if (!role) + goto out; + ctx->role = role->value; + + /* Extract type. */ + scontextp = p; + while (*p && *p != ':') + p++; + oldc = *p; + *p++ = 0; + + typdatum = symtab_search(&pol->p_types, scontextp); + if (!typdatum || typdatum->attribute) + goto out; + + ctx->type = typdatum->value; + + rc = mls_context_to_sid(pol, oldc, p, ctx, sidtabp, def_sid); + if (rc) + goto out; + + /* Check the validity of the new context. */ + rc = -EINVAL; + if (!policydb_context_isvalid(pol, ctx)) + goto out; + rc = 0; +out: + if (rc) + context_destroy(ctx); + return rc; +} + +static int security_context_to_sid_core(struct selinux_state *state, + const char *scontext, u32 scontext_len, + u32 *sid, u32 def_sid, gfp_t gfp_flags, + int force) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + char *scontext2, *str = NULL; + struct context context; + int rc = 0; + + /* An empty security context is never valid. */ + if (!scontext_len) + return -EINVAL; + + /* Copy the string to allow changes and ensure a NUL terminator */ + scontext2 = kmemdup_nul(scontext, scontext_len, gfp_flags); + if (!scontext2) + return -ENOMEM; + + if (!selinux_initialized(state)) { + int i; + + for (i = 1; i < SECINITSID_NUM; i++) { + const char *s = initial_sid_to_string[i]; + + if (s && !strcmp(s, scontext2)) { + *sid = i; + goto out; + } + } + *sid = SECINITSID_KERNEL; + goto out; + } + *sid = SECSID_NULL; + + if (force) { + /* Save another copy for storing in uninterpreted form */ + rc = -ENOMEM; + str = kstrdup(scontext2, gfp_flags); + if (!str) + goto out; + } +retry: + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + rc = string_to_context_struct(policydb, sidtab, scontext2, + &context, def_sid); + if (rc == -EINVAL && force) { + context.str = str; + context.len = strlen(str) + 1; + str = NULL; + } else if (rc) + goto out_unlock; + rc = sidtab_context_to_sid(sidtab, &context, sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + if (context.str) { + str = context.str; + context.str = NULL; + } + context_destroy(&context); + goto retry; + } + context_destroy(&context); +out_unlock: + rcu_read_unlock(); +out: + kfree(scontext2); + kfree(str); + return rc; +} + +/** + * security_context_to_sid - Obtain a SID for a given security context. + * @scontext: security context + * @scontext_len: length in bytes + * @sid: security identifier, SID + * @gfp: context for the allocation + * + * Obtains a SID associated with the security context that + * has the string representation specified by @scontext. + * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient + * memory is available, or 0 on success. + */ +int security_context_to_sid(struct selinux_state *state, + const char *scontext, u32 scontext_len, u32 *sid, + gfp_t gfp) +{ + return security_context_to_sid_core(state, scontext, scontext_len, + sid, SECSID_NULL, gfp, 0); +} + +int security_context_str_to_sid(struct selinux_state *state, + const char *scontext, u32 *sid, gfp_t gfp) +{ + return security_context_to_sid(state, scontext, strlen(scontext), + sid, gfp); +} + +/** + * security_context_to_sid_default - Obtain a SID for a given security context, + * falling back to specified default if needed. + * + * @scontext: security context + * @scontext_len: length in bytes + * @sid: security identifier, SID + * @def_sid: default SID to assign on error + * + * Obtains a SID associated with the security context that + * has the string representation specified by @scontext. + * The default SID is passed to the MLS layer to be used to allow + * kernel labeling of the MLS field if the MLS field is not present + * (for upgrading to MLS without full relabel). + * Implicitly forces adding of the context even if it cannot be mapped yet. + * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient + * memory is available, or 0 on success. + */ +int security_context_to_sid_default(struct selinux_state *state, + const char *scontext, u32 scontext_len, + u32 *sid, u32 def_sid, gfp_t gfp_flags) +{ + return security_context_to_sid_core(state, scontext, scontext_len, + sid, def_sid, gfp_flags, 1); +} + +int security_context_to_sid_force(struct selinux_state *state, + const char *scontext, u32 scontext_len, + u32 *sid) +{ + return security_context_to_sid_core(state, scontext, scontext_len, + sid, SECSID_NULL, GFP_KERNEL, 1); +} + +static int compute_sid_handle_invalid_context( + struct selinux_state *state, + struct selinux_policy *policy, + struct sidtab_entry *sentry, + struct sidtab_entry *tentry, + u16 tclass, + struct context *newcontext) +{ + struct policydb *policydb = &policy->policydb; + struct sidtab *sidtab = policy->sidtab; + char *s = NULL, *t = NULL, *n = NULL; + u32 slen, tlen, nlen; + struct audit_buffer *ab; + + if (sidtab_entry_to_string(policydb, sidtab, sentry, &s, &slen)) + goto out; + if (sidtab_entry_to_string(policydb, sidtab, tentry, &t, &tlen)) + goto out; + if (context_struct_to_string(policydb, newcontext, &n, &nlen)) + goto out; + ab = audit_log_start(audit_context(), GFP_ATOMIC, AUDIT_SELINUX_ERR); + audit_log_format(ab, + "op=security_compute_sid invalid_context="); + /* no need to record the NUL with untrusted strings */ + audit_log_n_untrustedstring(ab, n, nlen - 1); + audit_log_format(ab, " scontext=%s tcontext=%s tclass=%s", + s, t, sym_name(policydb, SYM_CLASSES, tclass-1)); + audit_log_end(ab); +out: + kfree(s); + kfree(t); + kfree(n); + if (!enforcing_enabled(state)) + return 0; + return -EACCES; +} + +static void filename_compute_type(struct policydb *policydb, + struct context *newcontext, + u32 stype, u32 ttype, u16 tclass, + const char *objname) +{ + struct filename_trans_key ft; + struct filename_trans_datum *datum; + + /* + * Most filename trans rules are going to live in specific directories + * like /dev or /var/run. This bitmap will quickly skip rule searches + * if the ttype does not contain any rules. + */ + if (!ebitmap_get_bit(&policydb->filename_trans_ttypes, ttype)) + return; + + ft.ttype = ttype; + ft.tclass = tclass; + ft.name = objname; + + datum = policydb_filenametr_search(policydb, &ft); + while (datum) { + if (ebitmap_get_bit(&datum->stypes, stype - 1)) { + newcontext->type = datum->otype; + return; + } + datum = datum->next; + } +} + +static int security_compute_sid(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 orig_tclass, + u32 specified, + const char *objname, + u32 *out_sid, + bool kern) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct class_datum *cladatum; + struct context *scontext, *tcontext, newcontext; + struct sidtab_entry *sentry, *tentry; + struct avtab_key avkey; + struct avtab_datum *avdatum; + struct avtab_node *node; + u16 tclass; + int rc = 0; + bool sock; + + if (!selinux_initialized(state)) { + switch (orig_tclass) { + case SECCLASS_PROCESS: /* kernel value */ + *out_sid = ssid; + break; + default: + *out_sid = tsid; + break; + } + goto out; + } + +retry: + cladatum = NULL; + context_init(&newcontext); + + rcu_read_lock(); + + policy = rcu_dereference(state->policy); + + if (kern) { + tclass = unmap_class(&policy->map, orig_tclass); + sock = security_is_socket_class(orig_tclass); + } else { + tclass = orig_tclass; + sock = security_is_socket_class(map_class(&policy->map, + tclass)); + } + + policydb = &policy->policydb; + sidtab = policy->sidtab; + + sentry = sidtab_search_entry(sidtab, ssid); + if (!sentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, ssid); + rc = -EINVAL; + goto out_unlock; + } + tentry = sidtab_search_entry(sidtab, tsid); + if (!tentry) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, tsid); + rc = -EINVAL; + goto out_unlock; + } + + scontext = &sentry->context; + tcontext = &tentry->context; + + if (tclass && tclass <= policydb->p_classes.nprim) + cladatum = policydb->class_val_to_struct[tclass - 1]; + + /* Set the user identity. */ + switch (specified) { + case AVTAB_TRANSITION: + case AVTAB_CHANGE: + if (cladatum && cladatum->default_user == DEFAULT_TARGET) { + newcontext.user = tcontext->user; + } else { + /* notice this gets both DEFAULT_SOURCE and unset */ + /* Use the process user identity. */ + newcontext.user = scontext->user; + } + break; + case AVTAB_MEMBER: + /* Use the related object owner. */ + newcontext.user = tcontext->user; + break; + } + + /* Set the role to default values. */ + if (cladatum && cladatum->default_role == DEFAULT_SOURCE) { + newcontext.role = scontext->role; + } else if (cladatum && cladatum->default_role == DEFAULT_TARGET) { + newcontext.role = tcontext->role; + } else { + if ((tclass == policydb->process_class) || sock) + newcontext.role = scontext->role; + else + newcontext.role = OBJECT_R_VAL; + } + + /* Set the type to default values. */ + if (cladatum && cladatum->default_type == DEFAULT_SOURCE) { + newcontext.type = scontext->type; + } else if (cladatum && cladatum->default_type == DEFAULT_TARGET) { + newcontext.type = tcontext->type; + } else { + if ((tclass == policydb->process_class) || sock) { + /* Use the type of process. */ + newcontext.type = scontext->type; + } else { + /* Use the type of the related object. */ + newcontext.type = tcontext->type; + } + } + + /* Look for a type transition/member/change rule. */ + avkey.source_type = scontext->type; + avkey.target_type = tcontext->type; + avkey.target_class = tclass; + avkey.specified = specified; + avdatum = avtab_search(&policydb->te_avtab, &avkey); + + /* If no permanent rule, also check for enabled conditional rules */ + if (!avdatum) { + node = avtab_search_node(&policydb->te_cond_avtab, &avkey); + for (; node; node = avtab_search_node_next(node, specified)) { + if (node->key.specified & AVTAB_ENABLED) { + avdatum = &node->datum; + break; + } + } + } + + if (avdatum) { + /* Use the type from the type transition/member/change rule. */ + newcontext.type = avdatum->u.data; + } + + /* if we have a objname this is a file trans check so check those rules */ + if (objname) + filename_compute_type(policydb, &newcontext, scontext->type, + tcontext->type, tclass, objname); + + /* Check for class-specific changes. */ + if (specified & AVTAB_TRANSITION) { + /* Look for a role transition rule. */ + struct role_trans_datum *rtd; + struct role_trans_key rtk = { + .role = scontext->role, + .type = tcontext->type, + .tclass = tclass, + }; + + rtd = policydb_roletr_search(policydb, &rtk); + if (rtd) + newcontext.role = rtd->new_role; + } + + /* Set the MLS attributes. + This is done last because it may allocate memory. */ + rc = mls_compute_sid(policydb, scontext, tcontext, tclass, specified, + &newcontext, sock); + if (rc) + goto out_unlock; + + /* Check the validity of the context. */ + if (!policydb_context_isvalid(policydb, &newcontext)) { + rc = compute_sid_handle_invalid_context(state, policy, sentry, + tentry, tclass, + &newcontext); + if (rc) + goto out_unlock; + } + /* Obtain the sid for the context. */ + rc = sidtab_context_to_sid(sidtab, &newcontext, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + context_destroy(&newcontext); + goto retry; + } +out_unlock: + rcu_read_unlock(); + context_destroy(&newcontext); +out: + return rc; +} + +/** + * security_transition_sid - Compute the SID for a new subject/object. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @out_sid: security identifier for new subject/object + * + * Compute a SID to use for labeling a new subject or object in the + * class @tclass based on a SID pair (@ssid, @tsid). + * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM + * if insufficient memory is available, or %0 if the new SID was + * computed successfully. + */ +int security_transition_sid(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + const struct qstr *qstr, u32 *out_sid) +{ + return security_compute_sid(state, ssid, tsid, tclass, + AVTAB_TRANSITION, + qstr ? qstr->name : NULL, out_sid, true); +} + +int security_transition_sid_user(struct selinux_state *state, + u32 ssid, u32 tsid, u16 tclass, + const char *objname, u32 *out_sid) +{ + return security_compute_sid(state, ssid, tsid, tclass, + AVTAB_TRANSITION, + objname, out_sid, false); +} + +/** + * security_member_sid - Compute the SID for member selection. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @out_sid: security identifier for selected member + * + * Compute a SID to use when selecting a member of a polyinstantiated + * object of class @tclass based on a SID pair (@ssid, @tsid). + * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM + * if insufficient memory is available, or %0 if the SID was + * computed successfully. + */ +int security_member_sid(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 tclass, + u32 *out_sid) +{ + return security_compute_sid(state, ssid, tsid, tclass, + AVTAB_MEMBER, NULL, + out_sid, false); +} + +/** + * security_change_sid - Compute the SID for object relabeling. + * @ssid: source security identifier + * @tsid: target security identifier + * @tclass: target security class + * @out_sid: security identifier for selected member + * + * Compute a SID to use for relabeling an object of class @tclass + * based on a SID pair (@ssid, @tsid). + * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM + * if insufficient memory is available, or %0 if the SID was + * computed successfully. + */ +int security_change_sid(struct selinux_state *state, + u32 ssid, + u32 tsid, + u16 tclass, + u32 *out_sid) +{ + return security_compute_sid(state, + ssid, tsid, tclass, AVTAB_CHANGE, NULL, + out_sid, false); +} + +static inline int convert_context_handle_invalid_context( + struct selinux_state *state, + struct policydb *policydb, + struct context *context) +{ + char *s; + u32 len; + + if (enforcing_enabled(state)) + return -EINVAL; + + if (!context_struct_to_string(policydb, context, &s, &len)) { + pr_warn("SELinux: Context %s would be invalid if enforcing\n", + s); + kfree(s); + } + return 0; +} + +/* + * Convert the values in the security context + * structure `oldc' from the values specified + * in the policy `p->oldp' to the values specified + * in the policy `p->newp', storing the new context + * in `newc'. Verify that the context is valid + * under the new policy. + */ +static int convert_context(struct context *oldc, struct context *newc, void *p, + gfp_t gfp_flags) +{ + struct convert_context_args *args; + struct ocontext *oc; + struct role_datum *role; + struct type_datum *typdatum; + struct user_datum *usrdatum; + char *s; + u32 len; + int rc; + + args = p; + + if (oldc->str) { + s = kstrdup(oldc->str, gfp_flags); + if (!s) + return -ENOMEM; + + rc = string_to_context_struct(args->newp, NULL, s, + newc, SECSID_NULL); + if (rc == -EINVAL) { + /* + * Retain string representation for later mapping. + * + * IMPORTANT: We need to copy the contents of oldc->str + * back into s again because string_to_context_struct() + * may have garbled it. + */ + memcpy(s, oldc->str, oldc->len); + context_init(newc); + newc->str = s; + newc->len = oldc->len; + return 0; + } + kfree(s); + if (rc) { + /* Other error condition, e.g. ENOMEM. */ + pr_err("SELinux: Unable to map context %s, rc = %d.\n", + oldc->str, -rc); + return rc; + } + pr_info("SELinux: Context %s became valid (mapped).\n", + oldc->str); + return 0; + } + + context_init(newc); + + /* Convert the user. */ + rc = -EINVAL; + usrdatum = symtab_search(&args->newp->p_users, + sym_name(args->oldp, + SYM_USERS, oldc->user - 1)); + if (!usrdatum) + goto bad; + newc->user = usrdatum->value; + + /* Convert the role. */ + rc = -EINVAL; + role = symtab_search(&args->newp->p_roles, + sym_name(args->oldp, SYM_ROLES, oldc->role - 1)); + if (!role) + goto bad; + newc->role = role->value; + + /* Convert the type. */ + rc = -EINVAL; + typdatum = symtab_search(&args->newp->p_types, + sym_name(args->oldp, + SYM_TYPES, oldc->type - 1)); + if (!typdatum) + goto bad; + newc->type = typdatum->value; + + /* Convert the MLS fields if dealing with MLS policies */ + if (args->oldp->mls_enabled && args->newp->mls_enabled) { + rc = mls_convert_context(args->oldp, args->newp, oldc, newc); + if (rc) + goto bad; + } else if (!args->oldp->mls_enabled && args->newp->mls_enabled) { + /* + * Switching between non-MLS and MLS policy: + * ensure that the MLS fields of the context for all + * existing entries in the sidtab are filled in with a + * suitable default value, likely taken from one of the + * initial SIDs. + */ + oc = args->newp->ocontexts[OCON_ISID]; + while (oc && oc->sid[0] != SECINITSID_UNLABELED) + oc = oc->next; + rc = -EINVAL; + if (!oc) { + pr_err("SELinux: unable to look up" + " the initial SIDs list\n"); + goto bad; + } + rc = mls_range_set(newc, &oc->context[0].range); + if (rc) + goto bad; + } + + /* Check the validity of the new context. */ + if (!policydb_context_isvalid(args->newp, newc)) { + rc = convert_context_handle_invalid_context(args->state, + args->oldp, + oldc); + if (rc) + goto bad; + } + + return 0; +bad: + /* Map old representation to string and save it. */ + rc = context_struct_to_string(args->oldp, oldc, &s, &len); + if (rc) + return rc; + context_destroy(newc); + newc->str = s; + newc->len = len; + pr_info("SELinux: Context %s became invalid (unmapped).\n", + newc->str); + return 0; +} + +static void security_load_policycaps(struct selinux_state *state, + struct selinux_policy *policy) +{ + struct policydb *p; + unsigned int i; + struct ebitmap_node *node; + + p = &policy->policydb; + + for (i = 0; i < ARRAY_SIZE(state->policycap); i++) + WRITE_ONCE(state->policycap[i], + ebitmap_get_bit(&p->policycaps, i)); + + for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) + pr_info("SELinux: policy capability %s=%d\n", + selinux_policycap_names[i], + ebitmap_get_bit(&p->policycaps, i)); + + ebitmap_for_each_positive_bit(&p->policycaps, node, i) { + if (i >= ARRAY_SIZE(selinux_policycap_names)) + pr_info("SELinux: unknown policy capability %u\n", + i); + } +} + +static int security_preserve_bools(struct selinux_policy *oldpolicy, + struct selinux_policy *newpolicy); + +static void selinux_policy_free(struct selinux_policy *policy) +{ + if (!policy) + return; + + sidtab_destroy(policy->sidtab); + kfree(policy->map.mapping); + policydb_destroy(&policy->policydb); + kfree(policy->sidtab); + kfree(policy); +} + +static void selinux_policy_cond_free(struct selinux_policy *policy) +{ + cond_policydb_destroy_dup(&policy->policydb); + kfree(policy); +} + +void selinux_policy_cancel(struct selinux_state *state, + struct selinux_load_state *load_state) +{ + struct selinux_policy *oldpolicy; + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + sidtab_cancel_convert(oldpolicy->sidtab); + selinux_policy_free(load_state->policy); + kfree(load_state->convert_data); +} + +static void selinux_notify_policy_change(struct selinux_state *state, + u32 seqno) +{ + /* Flush external caches and notify userspace of policy load */ + avc_ss_reset(state->avc, seqno); + selnl_notify_policyload(seqno); + selinux_status_update_policyload(state, seqno); + selinux_netlbl_cache_invalidate(); + selinux_xfrm_notify_policyload(); +} + +void selinux_policy_commit(struct selinux_state *state, + struct selinux_load_state *load_state) +{ + struct selinux_policy *oldpolicy, *newpolicy = load_state->policy; + unsigned long flags; + u32 seqno; + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* If switching between different policy types, log MLS status */ + if (oldpolicy) { + if (oldpolicy->policydb.mls_enabled && !newpolicy->policydb.mls_enabled) + pr_info("SELinux: Disabling MLS support...\n"); + else if (!oldpolicy->policydb.mls_enabled && newpolicy->policydb.mls_enabled) + pr_info("SELinux: Enabling MLS support...\n"); + } + + /* Set latest granting seqno for new policy. */ + if (oldpolicy) + newpolicy->latest_granting = oldpolicy->latest_granting + 1; + else + newpolicy->latest_granting = 1; + seqno = newpolicy->latest_granting; + + /* Install the new policy. */ + if (oldpolicy) { + sidtab_freeze_begin(oldpolicy->sidtab, &flags); + rcu_assign_pointer(state->policy, newpolicy); + sidtab_freeze_end(oldpolicy->sidtab, &flags); + } else { + rcu_assign_pointer(state->policy, newpolicy); + } + + /* Load the policycaps from the new policy */ + security_load_policycaps(state, newpolicy); + + if (!selinux_initialized(state)) { + /* + * After first policy load, the security server is + * marked as initialized and ready to handle requests and + * any objects created prior to policy load are then labeled. + */ + selinux_mark_initialized(state); + selinux_complete_init(); + } + + /* Free the old policy */ + synchronize_rcu(); + selinux_policy_free(oldpolicy); + kfree(load_state->convert_data); + + /* Notify others of the policy change */ + selinux_notify_policy_change(state, seqno); +} + +/** + * security_load_policy - Load a security policy configuration. + * @data: binary policy data + * @len: length of data in bytes + * + * Load a new set of security policy configuration data, + * validate it and convert the SID table as necessary. + * This function will flush the access vector cache after + * loading the new policy. + */ +int security_load_policy(struct selinux_state *state, void *data, size_t len, + struct selinux_load_state *load_state) +{ + struct selinux_policy *newpolicy, *oldpolicy; + struct selinux_policy_convert_data *convert_data; + int rc = 0; + struct policy_file file = { data, len }, *fp = &file; + + newpolicy = kzalloc(sizeof(*newpolicy), GFP_KERNEL); + if (!newpolicy) + return -ENOMEM; + + newpolicy->sidtab = kzalloc(sizeof(*newpolicy->sidtab), GFP_KERNEL); + if (!newpolicy->sidtab) { + rc = -ENOMEM; + goto err_policy; + } + + rc = policydb_read(&newpolicy->policydb, fp); + if (rc) + goto err_sidtab; + + newpolicy->policydb.len = len; + rc = selinux_set_mapping(&newpolicy->policydb, secclass_map, + &newpolicy->map); + if (rc) + goto err_policydb; + + rc = policydb_load_isids(&newpolicy->policydb, newpolicy->sidtab); + if (rc) { + pr_err("SELinux: unable to load the initial SIDs\n"); + goto err_mapping; + } + + if (!selinux_initialized(state)) { + /* First policy load, so no need to preserve state from old policy */ + load_state->policy = newpolicy; + load_state->convert_data = NULL; + return 0; + } + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* Preserve active boolean values from the old policy */ + rc = security_preserve_bools(oldpolicy, newpolicy); + if (rc) { + pr_err("SELinux: unable to preserve booleans\n"); + goto err_free_isids; + } + + convert_data = kmalloc(sizeof(*convert_data), GFP_KERNEL); + if (!convert_data) { + rc = -ENOMEM; + goto err_free_isids; + } + + /* + * Convert the internal representations of contexts + * in the new SID table. + */ + convert_data->args.state = state; + convert_data->args.oldp = &oldpolicy->policydb; + convert_data->args.newp = &newpolicy->policydb; + + convert_data->sidtab_params.func = convert_context; + convert_data->sidtab_params.args = &convert_data->args; + convert_data->sidtab_params.target = newpolicy->sidtab; + + rc = sidtab_convert(oldpolicy->sidtab, &convert_data->sidtab_params); + if (rc) { + pr_err("SELinux: unable to convert the internal" + " representation of contexts in the new SID" + " table\n"); + goto err_free_convert_data; + } + + load_state->policy = newpolicy; + load_state->convert_data = convert_data; + return 0; + +err_free_convert_data: + kfree(convert_data); +err_free_isids: + sidtab_destroy(newpolicy->sidtab); +err_mapping: + kfree(newpolicy->map.mapping); +err_policydb: + policydb_destroy(&newpolicy->policydb); +err_sidtab: + kfree(newpolicy->sidtab); +err_policy: + kfree(newpolicy); + + return rc; +} + +/** + * ocontext_to_sid - Helper to safely get sid for an ocontext + * @sidtab: SID table + * @c: ocontext structure + * @index: index of the context entry (0 or 1) + * @out_sid: pointer to the resulting SID value + * + * For all ocontexts except OCON_ISID the SID fields are populated + * on-demand when needed. Since updating the SID value is an SMP-sensitive + * operation, this helper must be used to do that safely. + * + * WARNING: This function may return -ESTALE, indicating that the caller + * must retry the operation after re-acquiring the policy pointer! + */ +static int ocontext_to_sid(struct sidtab *sidtab, struct ocontext *c, + size_t index, u32 *out_sid) +{ + int rc; + u32 sid; + + /* Ensure the associated sidtab entry is visible to this thread. */ + sid = smp_load_acquire(&c->sid[index]); + if (!sid) { + rc = sidtab_context_to_sid(sidtab, &c->context[index], &sid); + if (rc) + return rc; + + /* + * Ensure the new sidtab entry is visible to other threads + * when they see the SID. + */ + smp_store_release(&c->sid[index], sid); + } + *out_sid = sid; + return 0; +} + +/** + * security_port_sid - Obtain the SID for a port. + * @protocol: protocol number + * @port: port number + * @out_sid: security identifier + */ +int security_port_sid(struct selinux_state *state, + u8 protocol, u16 port, u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct ocontext *c; + int rc; + + if (!selinux_initialized(state)) { + *out_sid = SECINITSID_PORT; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_PORT]; + while (c) { + if (c->u.port.protocol == protocol && + c->u.port.low_port <= port && + c->u.port.high_port >= port) + break; + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else { + *out_sid = SECINITSID_PORT; + } + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_pkey_sid - Obtain the SID for a pkey. + * @subnet_prefix: Subnet Prefix + * @pkey_num: pkey number + * @out_sid: security identifier + */ +int security_ib_pkey_sid(struct selinux_state *state, + u64 subnet_prefix, u16 pkey_num, u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct ocontext *c; + int rc; + + if (!selinux_initialized(state)) { + *out_sid = SECINITSID_UNLABELED; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_IBPKEY]; + while (c) { + if (c->u.ibpkey.low_pkey <= pkey_num && + c->u.ibpkey.high_pkey >= pkey_num && + c->u.ibpkey.subnet_prefix == subnet_prefix) + break; + + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else + *out_sid = SECINITSID_UNLABELED; + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_ib_endport_sid - Obtain the SID for a subnet management interface. + * @dev_name: device name + * @port: port number + * @out_sid: security identifier + */ +int security_ib_endport_sid(struct selinux_state *state, + const char *dev_name, u8 port_num, u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct ocontext *c; + int rc; + + if (!selinux_initialized(state)) { + *out_sid = SECINITSID_UNLABELED; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_IBENDPORT]; + while (c) { + if (c->u.ibendport.port == port_num && + !strncmp(c->u.ibendport.dev_name, + dev_name, + IB_DEVICE_NAME_MAX)) + break; + + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else + *out_sid = SECINITSID_UNLABELED; + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_netif_sid - Obtain the SID for a network interface. + * @name: interface name + * @if_sid: interface SID + */ +int security_netif_sid(struct selinux_state *state, + char *name, u32 *if_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct ocontext *c; + + if (!selinux_initialized(state)) { + *if_sid = SECINITSID_NETIF; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_NETIF]; + while (c) { + if (strcmp(name, c->u.name) == 0) + break; + c = c->next; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, if_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else + *if_sid = SECINITSID_NETIF; + +out: + rcu_read_unlock(); + return rc; +} + +static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) +{ + int i, fail = 0; + + for (i = 0; i < 4; i++) + if (addr[i] != (input[i] & mask[i])) { + fail = 1; + break; + } + + return !fail; +} + +/** + * security_node_sid - Obtain the SID for a node (host). + * @domain: communication domain aka address family + * @addrp: address + * @addrlen: address length in bytes + * @out_sid: security identifier + */ +int security_node_sid(struct selinux_state *state, + u16 domain, + void *addrp, + u32 addrlen, + u32 *out_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct ocontext *c; + + if (!selinux_initialized(state)) { + *out_sid = SECINITSID_NODE; + return 0; + } + +retry: + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + switch (domain) { + case AF_INET: { + u32 addr; + + rc = -EINVAL; + if (addrlen != sizeof(u32)) + goto out; + + addr = *((u32 *)addrp); + + c = policydb->ocontexts[OCON_NODE]; + while (c) { + if (c->u.node.addr == (addr & c->u.node.mask)) + break; + c = c->next; + } + break; + } + + case AF_INET6: + rc = -EINVAL; + if (addrlen != sizeof(u64) * 2) + goto out; + c = policydb->ocontexts[OCON_NODE6]; + while (c) { + if (match_ipv6_addrmask(addrp, c->u.node6.addr, + c->u.node6.mask)) + break; + c = c->next; + } + break; + + default: + rc = 0; + *out_sid = SECINITSID_NODE; + goto out; + } + + if (c) { + rc = ocontext_to_sid(sidtab, c, 0, out_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else { + *out_sid = SECINITSID_NODE; + } + + rc = 0; +out: + rcu_read_unlock(); + return rc; +} + +#define SIDS_NEL 25 + +/** + * security_get_user_sids - Obtain reachable SIDs for a user. + * @fromsid: starting SID + * @username: username + * @sids: array of reachable SIDs for user + * @nel: number of elements in @sids + * + * Generate the set of SIDs for legal security contexts + * for a given user that can be reached by @fromsid. + * Set *@sids to point to a dynamically allocated + * array containing the set of SIDs. Set *@nel to the + * number of elements in the array. + */ + +int security_get_user_sids(struct selinux_state *state, + u32 fromsid, + char *username, + u32 **sids, + u32 *nel) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct context *fromcon, usercon; + u32 *mysids = NULL, *mysids2, sid; + u32 i, j, mynel, maxnel = SIDS_NEL; + struct user_datum *user; + struct role_datum *role; + struct ebitmap_node *rnode, *tnode; + int rc; + + *sids = NULL; + *nel = 0; + + if (!selinux_initialized(state)) + return 0; + + mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL); + if (!mysids) + return -ENOMEM; + +retry: + mynel = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + context_init(&usercon); + + rc = -EINVAL; + fromcon = sidtab_search(sidtab, fromsid); + if (!fromcon) + goto out_unlock; + + rc = -EINVAL; + user = symtab_search(&policydb->p_users, username); + if (!user) + goto out_unlock; + + usercon.user = user->value; + + ebitmap_for_each_positive_bit(&user->roles, rnode, i) { + role = policydb->role_val_to_struct[i]; + usercon.role = i + 1; + ebitmap_for_each_positive_bit(&role->types, tnode, j) { + usercon.type = j + 1; + + if (mls_setup_user_range(policydb, fromcon, user, + &usercon)) + continue; + + rc = sidtab_context_to_sid(sidtab, &usercon, &sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out_unlock; + if (mynel < maxnel) { + mysids[mynel++] = sid; + } else { + rc = -ENOMEM; + maxnel += SIDS_NEL; + mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); + if (!mysids2) + goto out_unlock; + memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); + kfree(mysids); + mysids = mysids2; + mysids[mynel++] = sid; + } + } + } + rc = 0; +out_unlock: + rcu_read_unlock(); + if (rc || !mynel) { + kfree(mysids); + return rc; + } + + rc = -ENOMEM; + mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); + if (!mysids2) { + kfree(mysids); + return rc; + } + for (i = 0, j = 0; i < mynel; i++) { + struct av_decision dummy_avd; + rc = avc_has_perm_noaudit(state, + fromsid, mysids[i], + SECCLASS_PROCESS, /* kernel value */ + PROCESS__TRANSITION, AVC_STRICT, + &dummy_avd); + if (!rc) + mysids2[j++] = mysids[i]; + cond_resched(); + } + kfree(mysids); + *sids = mysids2; + *nel = j; + return 0; +} + +/** + * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem + * @fstype: filesystem type + * @path: path from root of mount + * @sclass: file security class + * @sid: SID for path + * + * Obtain a SID to use for a file in a filesystem that + * cannot support xattr or use a fixed labeling behavior like + * transition SIDs or task SIDs. + * + * WARNING: This function may return -ESTALE, indicating that the caller + * must retry the operation after re-acquiring the policy pointer! + */ +static inline int __security_genfs_sid(struct selinux_policy *policy, + const char *fstype, + char *path, + u16 orig_sclass, + u32 *sid) +{ + struct policydb *policydb = &policy->policydb; + struct sidtab *sidtab = policy->sidtab; + int len; + u16 sclass; + struct genfs *genfs; + struct ocontext *c; + int cmp = 0; + + while (path[0] == '/' && path[1] == '/') + path++; + + sclass = unmap_class(&policy->map, orig_sclass); + *sid = SECINITSID_UNLABELED; + + for (genfs = policydb->genfs; genfs; genfs = genfs->next) { + cmp = strcmp(fstype, genfs->fstype); + if (cmp <= 0) + break; + } + + if (!genfs || cmp) + return -ENOENT; + + for (c = genfs->head; c; c = c->next) { + len = strlen(c->u.name); + if ((!c->v.sclass || sclass == c->v.sclass) && + (strncmp(c->u.name, path, len) == 0)) + break; + } + + if (!c) + return -ENOENT; + + return ocontext_to_sid(sidtab, c, 0, sid); +} + +/** + * security_genfs_sid - Obtain a SID for a file in a filesystem + * @fstype: filesystem type + * @path: path from root of mount + * @sclass: file security class + * @sid: SID for path + * + * Acquire policy_rwlock before calling __security_genfs_sid() and release + * it afterward. + */ +int security_genfs_sid(struct selinux_state *state, + const char *fstype, + char *path, + u16 orig_sclass, + u32 *sid) +{ + struct selinux_policy *policy; + int retval; + + if (!selinux_initialized(state)) { + *sid = SECINITSID_UNLABELED; + return 0; + } + + do { + rcu_read_lock(); + policy = rcu_dereference(state->policy); + retval = __security_genfs_sid(policy, fstype, path, + orig_sclass, sid); + rcu_read_unlock(); + } while (retval == -ESTALE); + return retval; +} + +int selinux_policy_genfs_sid(struct selinux_policy *policy, + const char *fstype, + char *path, + u16 orig_sclass, + u32 *sid) +{ + /* no lock required, policy is not yet accessible by other threads */ + return __security_genfs_sid(policy, fstype, path, orig_sclass, sid); +} + +/** + * security_fs_use - Determine how to handle labeling for a filesystem. + * @sb: superblock in question + */ +int security_fs_use(struct selinux_state *state, struct super_block *sb) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct ocontext *c; + struct superblock_security_struct *sbsec = sb->s_security; + const char *fstype = sb->s_type->name; + + if (!selinux_initialized(state)) { + sbsec->behavior = SECURITY_FS_USE_NONE; + sbsec->sid = SECINITSID_UNLABELED; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + c = policydb->ocontexts[OCON_FSUSE]; + while (c) { + if (strcmp(fstype, c->u.name) == 0) + break; + c = c->next; + } + + if (c) { + sbsec->behavior = c->v.behavior; + rc = ocontext_to_sid(sidtab, c, 0, &sbsec->sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + } else { + rc = __security_genfs_sid(policy, fstype, "/", + SECCLASS_DIR, &sbsec->sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) { + sbsec->behavior = SECURITY_FS_USE_NONE; + rc = 0; + } else { + sbsec->behavior = SECURITY_FS_USE_GENFS; + } + } + +out: + rcu_read_unlock(); + return rc; +} + +int security_get_bools(struct selinux_policy *policy, + u32 *len, char ***names, int **values) +{ + struct policydb *policydb; + u32 i; + int rc; + + policydb = &policy->policydb; + + *names = NULL; + *values = NULL; + + rc = 0; + *len = policydb->p_bools.nprim; + if (!*len) + goto out; + + rc = -ENOMEM; + *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); + if (!*names) + goto err; + + rc = -ENOMEM; + *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); + if (!*values) + goto err; + + for (i = 0; i < *len; i++) { + (*values)[i] = policydb->bool_val_to_struct[i]->state; + + rc = -ENOMEM; + (*names)[i] = kstrdup(sym_name(policydb, SYM_BOOLS, i), + GFP_ATOMIC); + if (!(*names)[i]) + goto err; + } + rc = 0; +out: + return rc; +err: + if (*names) { + for (i = 0; i < *len; i++) + kfree((*names)[i]); + kfree(*names); + } + kfree(*values); + *len = 0; + *names = NULL; + *values = NULL; + goto out; +} + + +int security_set_bools(struct selinux_state *state, u32 len, int *values) +{ + struct selinux_policy *newpolicy, *oldpolicy; + int rc; + u32 i, seqno = 0; + + if (!selinux_initialized(state)) + return -EINVAL; + + oldpolicy = rcu_dereference_protected(state->policy, + lockdep_is_held(&state->policy_mutex)); + + /* Consistency check on number of booleans, should never fail */ + if (WARN_ON(len != oldpolicy->policydb.p_bools.nprim)) + return -EINVAL; + + newpolicy = kmemdup(oldpolicy, sizeof(*newpolicy), GFP_KERNEL); + if (!newpolicy) + return -ENOMEM; + + /* + * Deep copy only the parts of the policydb that might be + * modified as a result of changing booleans. + */ + rc = cond_policydb_dup(&newpolicy->policydb, &oldpolicy->policydb); + if (rc) { + kfree(newpolicy); + return -ENOMEM; + } + + /* Update the boolean states in the copy */ + for (i = 0; i < len; i++) { + int new_state = !!values[i]; + int old_state = newpolicy->policydb.bool_val_to_struct[i]->state; + + if (new_state != old_state) { + audit_log(audit_context(), GFP_ATOMIC, + AUDIT_MAC_CONFIG_CHANGE, + "bool=%s val=%d old_val=%d auid=%u ses=%u", + sym_name(&newpolicy->policydb, SYM_BOOLS, i), + new_state, + old_state, + from_kuid(&init_user_ns, audit_get_loginuid(current)), + audit_get_sessionid(current)); + newpolicy->policydb.bool_val_to_struct[i]->state = new_state; + } + } + + /* Re-evaluate the conditional rules in the copy */ + evaluate_cond_nodes(&newpolicy->policydb); + + /* Set latest granting seqno for new policy */ + newpolicy->latest_granting = oldpolicy->latest_granting + 1; + seqno = newpolicy->latest_granting; + + /* Install the new policy */ + rcu_assign_pointer(state->policy, newpolicy); + + /* + * Free the conditional portions of the old policydb + * that were copied for the new policy, and the oldpolicy + * structure itself but not what it references. + */ + synchronize_rcu(); + selinux_policy_cond_free(oldpolicy); + + /* Notify others of the policy change */ + selinux_notify_policy_change(state, seqno); + return 0; +} + +int security_get_bool_value(struct selinux_state *state, + u32 index) +{ + struct selinux_policy *policy; + struct policydb *policydb; + int rc; + u32 len; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + + rc = -EFAULT; + len = policydb->p_bools.nprim; + if (index >= len) + goto out; + + rc = policydb->bool_val_to_struct[index]->state; +out: + rcu_read_unlock(); + return rc; +} + +static int security_preserve_bools(struct selinux_policy *oldpolicy, + struct selinux_policy *newpolicy) +{ + int rc, *bvalues = NULL; + char **bnames = NULL; + struct cond_bool_datum *booldatum; + u32 i, nbools = 0; + + rc = security_get_bools(oldpolicy, &nbools, &bnames, &bvalues); + if (rc) + goto out; + for (i = 0; i < nbools; i++) { + booldatum = symtab_search(&newpolicy->policydb.p_bools, + bnames[i]); + if (booldatum) + booldatum->state = bvalues[i]; + } + evaluate_cond_nodes(&newpolicy->policydb); + +out: + if (bnames) { + for (i = 0; i < nbools; i++) + kfree(bnames[i]); + } + kfree(bnames); + kfree(bvalues); + return rc; +} + +/* + * security_sid_mls_copy() - computes a new sid based on the given + * sid and the mls portion of mls_sid. + */ +int security_sid_mls_copy(struct selinux_state *state, + u32 sid, u32 mls_sid, u32 *new_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + struct context *context1; + struct context *context2; + struct context newcon; + char *s; + u32 len; + int rc; + + if (!selinux_initialized(state)) { + *new_sid = sid; + return 0; + } + +retry: + rc = 0; + context_init(&newcon); + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (!policydb->mls_enabled) { + *new_sid = sid; + goto out_unlock; + } + + rc = -EINVAL; + context1 = sidtab_search(sidtab, sid); + if (!context1) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, sid); + goto out_unlock; + } + + rc = -EINVAL; + context2 = sidtab_search(sidtab, mls_sid); + if (!context2) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, mls_sid); + goto out_unlock; + } + + newcon.user = context1->user; + newcon.role = context1->role; + newcon.type = context1->type; + rc = mls_context_cpy(&newcon, context2); + if (rc) + goto out_unlock; + + /* Check the validity of the new context. */ + if (!policydb_context_isvalid(policydb, &newcon)) { + rc = convert_context_handle_invalid_context(state, policydb, + &newcon); + if (rc) { + if (!context_struct_to_string(policydb, &newcon, &s, + &len)) { + struct audit_buffer *ab; + + ab = audit_log_start(audit_context(), + GFP_ATOMIC, + AUDIT_SELINUX_ERR); + audit_log_format(ab, + "op=security_sid_mls_copy invalid_context="); + /* don't record NUL with untrusted strings */ + audit_log_n_untrustedstring(ab, s, len - 1); + audit_log_end(ab); + kfree(s); + } + goto out_unlock; + } + } + rc = sidtab_context_to_sid(sidtab, &newcon, new_sid); + if (rc == -ESTALE) { + rcu_read_unlock(); + context_destroy(&newcon); + goto retry; + } +out_unlock: + rcu_read_unlock(); + context_destroy(&newcon); + return rc; +} + +/** + * security_net_peersid_resolve - Compare and resolve two network peer SIDs + * @nlbl_sid: NetLabel SID + * @nlbl_type: NetLabel labeling protocol type + * @xfrm_sid: XFRM SID + * + * Description: + * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be + * resolved into a single SID it is returned via @peer_sid and the function + * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function + * returns a negative value. A table summarizing the behavior is below: + * + * | function return | @sid + * ------------------------------+-----------------+----------------- + * no peer labels | 0 | SECSID_NULL + * single peer label | 0 | <peer_label> + * multiple, consistent labels | 0 | <peer_label> + * multiple, inconsistent labels | -<errno> | SECSID_NULL + * + */ +int security_net_peersid_resolve(struct selinux_state *state, + u32 nlbl_sid, u32 nlbl_type, + u32 xfrm_sid, + u32 *peer_sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct context *nlbl_ctx; + struct context *xfrm_ctx; + + *peer_sid = SECSID_NULL; + + /* handle the common (which also happens to be the set of easy) cases + * right away, these two if statements catch everything involving a + * single or absent peer SID/label */ + if (xfrm_sid == SECSID_NULL) { + *peer_sid = nlbl_sid; + return 0; + } + /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label + * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label + * is present */ + if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { + *peer_sid = xfrm_sid; + return 0; + } + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + /* + * We don't need to check initialized here since the only way both + * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the + * security server was initialized and state->initialized was true. + */ + if (!policydb->mls_enabled) { + rc = 0; + goto out; + } + + rc = -EINVAL; + nlbl_ctx = sidtab_search(sidtab, nlbl_sid); + if (!nlbl_ctx) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, nlbl_sid); + goto out; + } + rc = -EINVAL; + xfrm_ctx = sidtab_search(sidtab, xfrm_sid); + if (!xfrm_ctx) { + pr_err("SELinux: %s: unrecognized SID %d\n", + __func__, xfrm_sid); + goto out; + } + rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); + if (rc) + goto out; + + /* at present NetLabel SIDs/labels really only carry MLS + * information so if the MLS portion of the NetLabel SID + * matches the MLS portion of the labeled XFRM SID/label + * then pass along the XFRM SID as it is the most + * expressive */ + *peer_sid = xfrm_sid; +out: + rcu_read_unlock(); + return rc; +} + +static int get_classes_callback(void *k, void *d, void *args) +{ + struct class_datum *datum = d; + char *name = k, **classes = args; + int value = datum->value - 1; + + classes[value] = kstrdup(name, GFP_ATOMIC); + if (!classes[value]) + return -ENOMEM; + + return 0; +} + +int security_get_classes(struct selinux_policy *policy, + char ***classes, int *nclasses) +{ + struct policydb *policydb; + int rc; + + policydb = &policy->policydb; + + rc = -ENOMEM; + *nclasses = policydb->p_classes.nprim; + *classes = kcalloc(*nclasses, sizeof(**classes), GFP_ATOMIC); + if (!*classes) + goto out; + + rc = hashtab_map(&policydb->p_classes.table, get_classes_callback, + *classes); + if (rc) { + int i; + for (i = 0; i < *nclasses; i++) + kfree((*classes)[i]); + kfree(*classes); + } + +out: + return rc; +} + +static int get_permissions_callback(void *k, void *d, void *args) +{ + struct perm_datum *datum = d; + char *name = k, **perms = args; + int value = datum->value - 1; + + perms[value] = kstrdup(name, GFP_ATOMIC); + if (!perms[value]) + return -ENOMEM; + + return 0; +} + +int security_get_permissions(struct selinux_policy *policy, + char *class, char ***perms, int *nperms) +{ + struct policydb *policydb; + int rc, i; + struct class_datum *match; + + policydb = &policy->policydb; + + rc = -EINVAL; + match = symtab_search(&policydb->p_classes, class); + if (!match) { + pr_err("SELinux: %s: unrecognized class %s\n", + __func__, class); + goto out; + } + + rc = -ENOMEM; + *nperms = match->permissions.nprim; + *perms = kcalloc(*nperms, sizeof(**perms), GFP_ATOMIC); + if (!*perms) + goto out; + + if (match->comdatum) { + rc = hashtab_map(&match->comdatum->permissions.table, + get_permissions_callback, *perms); + if (rc) + goto err; + } + + rc = hashtab_map(&match->permissions.table, get_permissions_callback, + *perms); + if (rc) + goto err; + +out: + return rc; + +err: + for (i = 0; i < *nperms; i++) + kfree((*perms)[i]); + kfree(*perms); + return rc; +} + +int security_get_reject_unknown(struct selinux_state *state) +{ + struct selinux_policy *policy; + int value; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + value = policy->policydb.reject_unknown; + rcu_read_unlock(); + return value; +} + +int security_get_allow_unknown(struct selinux_state *state) +{ + struct selinux_policy *policy; + int value; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + value = policy->policydb.allow_unknown; + rcu_read_unlock(); + return value; +} + +/** + * security_policycap_supported - Check for a specific policy capability + * @req_cap: capability + * + * Description: + * This function queries the currently loaded policy to see if it supports the + * capability specified by @req_cap. Returns true (1) if the capability is + * supported, false (0) if it isn't supported. + * + */ +int security_policycap_supported(struct selinux_state *state, + unsigned int req_cap) +{ + struct selinux_policy *policy; + int rc; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + rc = ebitmap_get_bit(&policy->policydb.policycaps, req_cap); + rcu_read_unlock(); + + return rc; +} + +struct selinux_audit_rule { + u32 au_seqno; + struct context au_ctxt; +}; + +void selinux_audit_rule_free(void *vrule) +{ + struct selinux_audit_rule *rule = vrule; + + if (rule) { + context_destroy(&rule->au_ctxt); + kfree(rule); + } +} + +int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *policy; + struct policydb *policydb; + struct selinux_audit_rule *tmprule; + struct role_datum *roledatum; + struct type_datum *typedatum; + struct user_datum *userdatum; + struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; + int rc = 0; + + *rule = NULL; + + if (!selinux_initialized(state)) + return -EOPNOTSUPP; + + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + /* only 'equals' and 'not equals' fit user, role, and type */ + if (op != Audit_equal && op != Audit_not_equal) + return -EINVAL; + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + /* we do not allow a range, indicated by the presence of '-' */ + if (strchr(rulestr, '-')) + return -EINVAL; + break; + default: + /* only the above fields are valid */ + return -EINVAL; + } + + tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); + if (!tmprule) + return -ENOMEM; + + context_init(&tmprule->au_ctxt); + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + + tmprule->au_seqno = policy->latest_granting; + + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_OBJ_USER: + rc = -EINVAL; + userdatum = symtab_search(&policydb->p_users, rulestr); + if (!userdatum) + goto out; + tmprule->au_ctxt.user = userdatum->value; + break; + case AUDIT_SUBJ_ROLE: + case AUDIT_OBJ_ROLE: + rc = -EINVAL; + roledatum = symtab_search(&policydb->p_roles, rulestr); + if (!roledatum) + goto out; + tmprule->au_ctxt.role = roledatum->value; + break; + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_TYPE: + rc = -EINVAL; + typedatum = symtab_search(&policydb->p_types, rulestr); + if (!typedatum) + goto out; + tmprule->au_ctxt.type = typedatum->value; + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + rc = mls_from_string(policydb, rulestr, &tmprule->au_ctxt, + GFP_ATOMIC); + if (rc) + goto out; + break; + } + rc = 0; +out: + rcu_read_unlock(); + + if (rc) { + selinux_audit_rule_free(tmprule); + tmprule = NULL; + } + + *rule = tmprule; + + return rc; +} + +/* Check to see if the rule contains any selinux fields */ +int selinux_audit_rule_known(struct audit_krule *rule) +{ + int i; + + for (i = 0; i < rule->field_count; i++) { + struct audit_field *f = &rule->fields[i]; + switch (f->type) { + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + return 1; + } + } + + return 0; +} + +int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule) +{ + struct selinux_state *state = &selinux_state; + struct selinux_policy *policy; + struct context *ctxt; + struct mls_level *level; + struct selinux_audit_rule *rule = vrule; + int match = 0; + + if (unlikely(!rule)) { + WARN_ONCE(1, "selinux_audit_rule_match: missing rule\n"); + return -ENOENT; + } + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + + policy = rcu_dereference(state->policy); + + if (rule->au_seqno < policy->latest_granting) { + match = -ESTALE; + goto out; + } + + ctxt = sidtab_search(policy->sidtab, sid); + if (unlikely(!ctxt)) { + WARN_ONCE(1, "selinux_audit_rule_match: unrecognized SID %d\n", + sid); + match = -ENOENT; + goto out; + } + + /* a field/op pair that is not caught here will simply fall through + without a match */ + switch (field) { + case AUDIT_SUBJ_USER: + case AUDIT_OBJ_USER: + switch (op) { + case Audit_equal: + match = (ctxt->user == rule->au_ctxt.user); + break; + case Audit_not_equal: + match = (ctxt->user != rule->au_ctxt.user); + break; + } + break; + case AUDIT_SUBJ_ROLE: + case AUDIT_OBJ_ROLE: + switch (op) { + case Audit_equal: + match = (ctxt->role == rule->au_ctxt.role); + break; + case Audit_not_equal: + match = (ctxt->role != rule->au_ctxt.role); + break; + } + break; + case AUDIT_SUBJ_TYPE: + case AUDIT_OBJ_TYPE: + switch (op) { + case Audit_equal: + match = (ctxt->type == rule->au_ctxt.type); + break; + case Audit_not_equal: + match = (ctxt->type != rule->au_ctxt.type); + break; + } + break; + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + level = ((field == AUDIT_SUBJ_SEN || + field == AUDIT_OBJ_LEV_LOW) ? + &ctxt->range.level[0] : &ctxt->range.level[1]); + switch (op) { + case Audit_equal: + match = mls_level_eq(&rule->au_ctxt.range.level[0], + level); + break; + case Audit_not_equal: + match = !mls_level_eq(&rule->au_ctxt.range.level[0], + level); + break; + case Audit_lt: + match = (mls_level_dom(&rule->au_ctxt.range.level[0], + level) && + !mls_level_eq(&rule->au_ctxt.range.level[0], + level)); + break; + case Audit_le: + match = mls_level_dom(&rule->au_ctxt.range.level[0], + level); + break; + case Audit_gt: + match = (mls_level_dom(level, + &rule->au_ctxt.range.level[0]) && + !mls_level_eq(level, + &rule->au_ctxt.range.level[0])); + break; + case Audit_ge: + match = mls_level_dom(level, + &rule->au_ctxt.range.level[0]); + break; + } + } + +out: + rcu_read_unlock(); + return match; +} + +static int (*aurule_callback)(void) = audit_update_lsm_rules; + +static int aurule_avc_callback(u32 event) +{ + int err = 0; + + if (event == AVC_CALLBACK_RESET && aurule_callback) + err = aurule_callback(); + return err; +} + +static int __init aurule_init(void) +{ + int err; + + err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET); + if (err) + panic("avc_add_callback() failed, error %d\n", err); + + return err; +} +__initcall(aurule_init); + +#ifdef CONFIG_NETLABEL +/** + * security_netlbl_cache_add - Add an entry to the NetLabel cache + * @secattr: the NetLabel packet security attributes + * @sid: the SELinux SID + * + * Description: + * Attempt to cache the context in @ctx, which was derived from the packet in + * @skb, in the NetLabel subsystem cache. This function assumes @secattr has + * already been initialized. + * + */ +static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, + u32 sid) +{ + u32 *sid_cache; + + sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); + if (sid_cache == NULL) + return; + secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); + if (secattr->cache == NULL) { + kfree(sid_cache); + return; + } + + *sid_cache = sid; + secattr->cache->free = kfree; + secattr->cache->data = sid_cache; + secattr->flags |= NETLBL_SECATTR_CACHE; +} + +/** + * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID + * @secattr: the NetLabel packet security attributes + * @sid: the SELinux SID + * + * Description: + * Convert the given NetLabel security attributes in @secattr into a + * SELinux SID. If the @secattr field does not contain a full SELinux + * SID/context then use SECINITSID_NETMSG as the foundation. If possible the + * 'cache' field of @secattr is set and the CACHE flag is set; this is to + * allow the @secattr to be used by NetLabel to cache the secattr to SID + * conversion for future lookups. Returns zero on success, negative values on + * failure. + * + */ +int security_netlbl_secattr_to_sid(struct selinux_state *state, + struct netlbl_lsm_secattr *secattr, + u32 *sid) +{ + struct selinux_policy *policy; + struct policydb *policydb; + struct sidtab *sidtab; + int rc; + struct context *ctx; + struct context ctx_new; + + if (!selinux_initialized(state)) { + *sid = SECSID_NULL; + return 0; + } + +retry: + rc = 0; + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + sidtab = policy->sidtab; + + if (secattr->flags & NETLBL_SECATTR_CACHE) + *sid = *(u32 *)secattr->cache->data; + else if (secattr->flags & NETLBL_SECATTR_SECID) + *sid = secattr->attr.secid; + else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { + rc = -EIDRM; + ctx = sidtab_search(sidtab, SECINITSID_NETMSG); + if (ctx == NULL) + goto out; + + context_init(&ctx_new); + ctx_new.user = ctx->user; + ctx_new.role = ctx->role; + ctx_new.type = ctx->type; + mls_import_netlbl_lvl(policydb, &ctx_new, secattr); + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { + rc = mls_import_netlbl_cat(policydb, &ctx_new, secattr); + if (rc) + goto out; + } + rc = -EIDRM; + if (!mls_context_isvalid(policydb, &ctx_new)) { + ebitmap_destroy(&ctx_new.range.level[0].cat); + goto out; + } + + rc = sidtab_context_to_sid(sidtab, &ctx_new, sid); + ebitmap_destroy(&ctx_new.range.level[0].cat); + if (rc == -ESTALE) { + rcu_read_unlock(); + goto retry; + } + if (rc) + goto out; + + security_netlbl_cache_add(secattr, *sid); + } else + *sid = SECSID_NULL; + +out: + rcu_read_unlock(); + return rc; +} + +/** + * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr + * @sid: the SELinux SID + * @secattr: the NetLabel packet security attributes + * + * Description: + * Convert the given SELinux SID in @sid into a NetLabel security attribute. + * Returns zero on success, negative values on failure. + * + */ +int security_netlbl_sid_to_secattr(struct selinux_state *state, + u32 sid, struct netlbl_lsm_secattr *secattr) +{ + struct selinux_policy *policy; + struct policydb *policydb; + int rc; + struct context *ctx; + + if (!selinux_initialized(state)) + return 0; + + rcu_read_lock(); + policy = rcu_dereference(state->policy); + policydb = &policy->policydb; + + rc = -ENOENT; + ctx = sidtab_search(policy->sidtab, sid); + if (ctx == NULL) + goto out; + + rc = -ENOMEM; + secattr->domain = kstrdup(sym_name(policydb, SYM_TYPES, ctx->type - 1), + GFP_ATOMIC); + if (secattr->domain == NULL) + goto out; + + secattr->attr.secid = sid; + secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; + mls_export_netlbl_lvl(policydb, ctx, secattr); + rc = mls_export_netlbl_cat(policydb, ctx, secattr); +out: + rcu_read_unlock(); + return rc; +} +#endif /* CONFIG_NETLABEL */ + +/** + * security_read_policy - read the policy. + * @data: binary policy data + * @len: length of data in bytes + * + */ +int security_read_policy(struct selinux_state *state, + void **data, size_t *len) +{ + struct selinux_policy *policy; + int rc; + struct policy_file fp; + + policy = rcu_dereference_protected( + state->policy, lockdep_is_held(&state->policy_mutex)); + if (!policy) + return -EINVAL; + + *len = policy->policydb.len; + *data = vmalloc_user(*len); + if (!*data) + return -ENOMEM; + + fp.data = *data; + fp.len = *len; + + rc = policydb_write(&policy->policydb, &fp); + if (rc) + return rc; + + *len = (unsigned long)fp.data - (unsigned long)*data; + return 0; + +} |